| 摘要 |
PROBLEM TO BE SOLVED: To provide a forging method for remedying the internal defect of a forged material such as a crank throw by concentrating stress and strain on the inside of a workpiece and efficiently performing stoppage of the defect in the inside, especially a center part such a pin part. SOLUTION: The forging method is provided for forging the workpiece 3 while performing a plurality of times of pass operations in which reduction of the workpiece 3 from two directions opposite from each other and a feeding operation of the workpiece 3 in the direction of the same axis are repeated alternately by means of a free forging press on which flat anvils 1, 2 are mounted. In the forging method, the internal defect of the forged material is remedied by performing the reduction of the workpiece 3 while cooling it in such a way that the range of temperature difference between the temperature before starting the reduction and the temperature after completing the reduction at the side faces Sc corresponding to the surfaces Ua to be reduced of the workpiece 3 is 25-300°C. COPYRIGHT: (C)2011,JPO&INPIT |
